Mimicry and Camouflage

Camouflage:any strategy used for concealment or to prevent detection. It is an animal’s ability to hide from predators and from prey. It increases an animal’s chances of survival and therefore also of reproduction. Mimicry is a subtype of camouflage, in which an animal masquerades as another to avoid detection.

Crypsis: the use of colours and patterns to prevent detection

Types of Camouflage:

Background Matching: appearing the same colour, patter, texture etc. of a given background

Disruptive Colouration: bold shapes and patterns that distort recognition of an animal’s true outline. Confuses predators as to where the animal starts and ends.

Motion Dazzle: Bold patterns such as zebra stripes which when in motion cause an animal’s true speed and direction to be distorted

Countershading: Two tones of colour on different areas of the body to account of directional sunlight (ex. Sharks are darken on top so looking down they blend with the water while light on the bottom so looking up they blend with the sunlight)

Camouflage is different based on:

Environment: type of background to blend in with

Animals Physiology: type of skin(fur, scales, feathers etc.)

Animal Behaviour:How they move in their environment, how they hunt

Animal being evaded: How the animal hunts, senses predators/prey, etc.

Changing Colours:

With the seasons: to camouflage with the new environment (e.g. Some types of wild rabbits being white in winter to blend in with the snow, then turning brown in spring to blend with dirt)

Based on surroundings

Changed by: o Shedding a layer o Change in diet o Releasing hormones based on the environment o Activating different chromatophores with coloured pigments

Mimicry

Mimicry is the resemblance which certain animals and plants exhibit to other animals and plants or to

the natural objects among which they live, a characteristic which serves as their chief means of

protection against enemies. There are three forms of mimicry utilized by both predator and prey:

Batesian mimicry, Muellerian mimicry, and self-mimicry

Batesian mimicry is named for Henry Walter Bates, a British scientist who studied mimicry in Amazonian

butterflies during the mid- and late nineteenth century. It refers to two or more species that are similar

in appearance, but only one of which is armed with spines, stingers, or toxic chemistry, while its

apparent double lacks these traits. The second species has no defense other than resembling the

unpalatable species and is afforded protection from certain predators by its resemblance to the

unpalatable species, which the predator associates with a certain appearance and a bad experience. An

example of this type of mimicry is the syrphid fly and the honey bee. The Syrphid fly mimics the colors

and markings of honey bees, therefore giving the connection of having a stinger and other defense

mechanisms of a honey bee.

Muellerian mimicry is named for Fritz Mueller, a German zoologist who worked in the Amazon three

decades after Bates. This form of mimicry refers to two unpalatable species that are mimics of each

other with conspicuous warning coloration (also known as aposematic coloration). Thus all mimics share

the benefits of the coloration since the predator will recognize the coloration of an unpalatable group

after a few bad experiences. Since several species have the same appearance to the predator, the loss of

life will be spread out over several species, reducing the impact on each individual species. An example

of this type of mimicry is the Monarch butterfly and the Viceroy butterfly. Viceroys find protection

through resemblance of the Monarch with the similar cautioning bright colours, warning predators of

danger and previous bad experiences.

Self-mimicry is a misleading term for animals that have one body part that mimics another to increase

survival during an attack or helps predators appear innocuous. For example, countless moth, butterfly,

and freshwater fish species have "eye-spots", large dark markings that when flashed may momentarily

startle a predator and allow the prey extra seconds to escape. "Eye-spots" also help prey escape

predators by giving predators a false target. A butterfly has a better chance of surviving an attack to the

outer part of its wing than an attack to the head.

How Camouflage Evolved

An arms race: The camouflaging species is constantly under natural selection for being a good

hider. The species it is trying to evade is under natural selection for being able to tell the

difference between its prey and a rock.

Constantly ongoing: Due to this natural selection, species are constantly getting better at

camouflage while other species are constantly getting better at spotting camouflaged animals.